The present invention relates to an integrated telephone transmission and switching system and more particularly to a subscriber terminal for making connections between a plurality of local subscriber lines and a central office local subscriber switch.
Referring to the cross-referenced application entitled "Integrated Transmission and Switching System", there is provided therein a system for making digital connections between local subscriber lines and any other subscriber line in the system. That system includes a central office base switch connected to a plurality of multi-time slot digital data buses, commonly known as T-1 lines, for switching encoded data between any of the time slots, using pulse code modulated (PCM) switching techniques. In order to make connections between a local level and any other subscriber line in the system, a subscriber switch is desirable for connecting a plurality of local subscriber lines to specified time slots on a T-1 line. This enables the base switch to make the interconnections with any other time slot in the system. To achieve such a switching system, there is need for a subscriber terminal capable of interchanging and concentrating a plurality of subscriber lines to specified time slots on T-1 lines.
In view of the above background, it is an objective of the present invention to provide a subscriber terminal for concentrating and connecting a plurality of local subscriber lines to specified time slots on a multitime slot digital data bus, thereby enabling digital connections to the any subscriber line in the system.